It is a musculoskeletal disorder which affects 80% of people. Important structures in the lower area of the back includes lumbar spine and their intervertrebral discs, spinal cords and nerves, ligaments, muscles of lower back, internal organs of pelvis and skin of the lower area. On each side, there is sacrum, a bone which meets the illiac part of the pubic bone and forms the sacro iliac joints of the buttocks.The discs between the vertebrae acts as a cushions or shock absorbers and minimize the stress over there.
Ligaments are the strong fibrous tissue that joins bones. Ligaments attach of the vertebrae to each other and surround each of the discs. The nerves emerges from the spinal cord can be compressed. The aorta and blood vessels carry blood from the lower extremities to the heart and from the heart.
Many muscles in the back are responsible for the movements of waist and the legs. The low back helps in the movement and protection of various organs like uterus, prostate,etc and various other important structures like nerves arising from the spinal cord.

The important causes include the skeletal degeneration or injury in the ligaments and muscles.They are usually non specific.
Causes include:

    * Degeneration of the disc
    * Slipped disc
    * Fractures in the bones of pelvis
    * Some immunity related diseases like ankylosis spondylitis
    * Rheumatoid arthritis
    * Some neoplastic tumours like bone tumours.
    * Osteoporotic fractures
    * Sometimes there is refered pain in the from the pelvic organs..

    * As there are many muscles in the back which on strenuous exercises can create tension in the nerves and hence these should be avoided.
    * low impact activities such as swimming, running, bicycling can increase the overall fitness without having too much strain on the back.
    * There are some specific exercises like abdominal crunches can decrease low back pain and they help to strengthen the abdominal muscles also.
    * Belts are available which supports the back called lumbar support belts.
    * while sitting in the car some comfort to the back is given by adjusting the seats or with the pillows. Chairs used for sitting must be of proper height to fully support the back.
    * Bed must not be too hard or soft to sleep.
    * Avoid lifting heavy objects. A technique should be attempted to lift heavy objects in which there is straight back, head up and object is being lifted by folding knees and don't stoop to lift it up.